The U.S. Marine Corps is launching an internal investigation into the culture of the Corps in response to a video that purportedly shows troops urinating on the corpses of suspected Taliban fighters, a Marine official told ABC News today.

The probe will attempt to answer the question "What happened in the Marine Corps that this happened?" according to the official.

"It'll be a holistic look at everything surrounding this issue," he said.

USMC Commandant Gen. Jim Amos first announced an internal "preliminary" probe Thursday, saying the video showed behavior "wholly inconsistent with the high standards of conduct and warrior ethos that we have demonstrated throughout our history."

The video, which surfaced online Wednesday, appears to show four men in uniform looking around before urinating on three dead bodies. At least one of the men chuckles as they do so.

The Naval Criminal Investigative Service (NCIS) has already launched its own independent investigation into potential criminal activity shown in the video. All four Marines featured in the video have been identified and interviewed by investigators with the NCIS, the service said in a statement today. Officials are "still tracking down" whoever created and uploaded the video, the NCIS said.

The results of both the NCIS and the USMC investigations will be presented to Marine Lt. Gen. Thomas Waldhauser who will determine further action, the USMC said in a statement.

If authentic, the video portrays potential violations of both the first Geneva Convention, which calls for the dead to be "honorably interred" and graves to be "respected," as well as the U.S. Uniform Code of Military Justice for allegedly bringing "discredit upon the armed forces."

Eugene Fidell, who teaches military justice at Yale University, said the Marines will most likely be charged under an interpretation of the Uniform Code for Military Justice and any prison sentences would depend on instructions a military judge will give a jury of military officers who then determine the sentence.

On one of the first websites to feature the video, the member who posted it identified the Marines as belonging to the 3/2 Marine battalion out of Camp Lejeune, an assertion later confirmed by the U.S. Marine Corps (USMC). The battalion served in the northern Helmand Province in Afghanistan last summer. The USMC declined to identify the individual Marines in the video.

After its anonymous release, the video was roundly condemned by top American and foreign officials.

U.S. Secretary of Defense Leon Panetta called it "deplorable" and Secretary of State Hillary Clinton said she felt "total dismay" after hearing the story.

"It is absolutely inconsistent with American values, with the standards of behavior that we expect from our military personnel and the vast, vast military personnel, particularly our Marines, hold themselves to," she said Thursday.